1
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Biphotochromic and ionochromic benzoxazolyl-substituted spirobipyrans. J Photochem Photobiol A Chem 2021. [DOI: 10.1016/j.jphotochem.2021.113259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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2
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Kar S, Shivalingegowda N, Krishnappagowda LN, Golakoti NR. SiCl4mediated one-pot synthesis of novel spirobibenzopyrans as potent anticancer agents. NEW J CHEM 2019. [DOI: 10.1039/c8nj06444j] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
This study is the first report on the anticancer activity of spirobibenzopyrans, an unexplored class of therapeutic agents.
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Affiliation(s)
- Swayamsiddha Kar
- Department of Chemistry
- Sri Sathya Sai Institute of Higher Learning
- Prasanthi Nilayam
- India
| | - Naveen Shivalingegowda
- Department of Physics
- School of Engineering & Technology
- Jain University
- Bangalore 562 112
- India
| | | | - Nageswara Rao Golakoti
- Department of Chemistry
- Sri Sathya Sai Institute of Higher Learning
- Prasanthi Nilayam
- India
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3
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Lindamulage De Silva A, Risso V, Jean M, Giorgi M, Monnier V, Naubron JV, Vanthuyne N, Farran D, Roussel C. A forgotten chiral spiro compound revisited: 3,3'-dimethyl-3H,3'H-2,2'-spirobi[[1,3]benzothiazole]. Chirality 2015; 27:716-21. [PMID: 26415851 DOI: 10.1002/chir.22492] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2015] [Revised: 07/06/2015] [Accepted: 07/09/2015] [Indexed: 11/09/2022]
Abstract
The title compound was obtained as a side product during dimerization-oxidation steps of the carbene generated from N-methylbenzothiazolium iodide. Chromatography on (S,S)-Whelk O1 column showed on cooling a typical plateau shape chromatogram indicating an exchange between two enantiomers on the column. The thermal barrier to racemization was determined (85 kJ.mol(-1) at 10 °C) by dynamic high-performance liquid chromatography (DHPLC).The absolute configuration of the first (M) and second eluted (P) enantiomers on the (S, S)-Whelk O1 column was established by comparing the reconstructed circular dichroism (CD) spectra from the CD detector signal and the calculated CD spectrum of the (P) enantiomer. Mass spectrometry revealed that 3,3'-dimethyl-3H,3'H-2,2'-spirobi[[1,3]benzothiazole] can be viewed as a masked thiophenate attached to a benzothiazolium framework.
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Affiliation(s)
| | - Vesna Risso
- Aix Marseille Université, Centrale Marseille, CNRS, iSm2 UMR 7313, 13397, Marseille, France
| | - Marion Jean
- Aix Marseille Université, Centrale Marseille, CNRS, iSm2 UMR 7313, 13397, Marseille, France
| | - Michel Giorgi
- Spectropôle, Aix Marseille Université, Marseille, France
| | | | | | - Nicolas Vanthuyne
- Aix Marseille Université, Centrale Marseille, CNRS, iSm2 UMR 7313, 13397, Marseille, France
| | - Daniel Farran
- Aix Marseille Université, Centrale Marseille, CNRS, iSm2 UMR 7313, 13397, Marseille, France
| | - Christian Roussel
- Aix Marseille Université, Centrale Marseille, CNRS, iSm2 UMR 7313, 13397, Marseille, France
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4
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Moro AJ, Pana AM, Cseh L, Costisor O, Parola J, Cunha-Silva L, Puttreddy R, Rissanen K, Pina F. Chemistry and Photochemistry of 2,6-Bis(2-hydroxybenzilidene)cyclohexanone. An Example of a Compound Following the Anthocyanins Network of Chemical Reactions. J Phys Chem A 2014; 118:6208-15. [DOI: 10.1021/jp505533b] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Artur J. Moro
- REQUIMTE,
Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Monte de Caparica, Portugal
| | - Ana-Maria Pana
- Institute of Chemistry Timisoara of Romanian Academy, 24 MihaiViteazul Bvd, 300223 Timisoara, Romania
| | - Liliana Cseh
- Institute of Chemistry Timisoara of Romanian Academy, 24 MihaiViteazul Bvd, 300223 Timisoara, Romania
| | - Otilia Costisor
- Institute of Chemistry Timisoara of Romanian Academy, 24 MihaiViteazul Bvd, 300223 Timisoara, Romania
| | - Jorge Parola
- REQUIMTE,
Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Monte de Caparica, Portugal
| | - L. Cunha-Silva
- REQUIMTE,
Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, 4169-007 Porto, Portugal
| | - Rakesh Puttreddy
- Department
of Chemistry, Nanoscience Center, University of Jyväskylä, 40014 Jyväskylä, Finland
| | - Kari Rissanen
- Department
of Chemistry, Nanoscience Center, University of Jyväskylä, 40014 Jyväskylä, Finland
| | - Fernando Pina
- REQUIMTE,
Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Monte de Caparica, Portugal
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5
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Voloshin NA, Solov’eva EV, Bezugliy SO, Metelitsa AV, Minkin VI. Photo- and thermochromic spirans 37.* New symmetrical bisspiropyrans of the indoline series. Chem Heterocycl Compd (N Y) 2012. [DOI: 10.1007/s10593-012-1145-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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6
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Xu L, Mikami K. Diastereo- and enantioselective syntheses of ansa-metallocenes from metal halide complexes with tropos biphenol and atropos binaphthol ethers. Tetrahedron Lett 2004. [DOI: 10.1016/j.tetlet.2004.10.094] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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7
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Raić-Malić S, Tomasković L, Mrvos-Sermek D, Prugovecki B, Cetina M, Grdisa M, Pavelić K, Mannschreck A, Balzarini J, De Clercq E, Mintas M. Spirobipyridopyrans, spirobinaphthopyrans, indolinospiropyridopyrans, indolinospironaphthopyrans and indolinospironaphtho-1,4-oxazines: synthesis, study of X-ray crystal structure, antitumoral and antiviral evaluation. Bioorg Med Chem 2004; 12:1037-45. [PMID: 14980617 DOI: 10.1016/j.bmc.2003.12.010] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2003] [Accepted: 12/09/2003] [Indexed: 11/20/2022]
Abstract
The novel racemic indolinospirobenzopyrans (5-7), indolinospironaphthopyrans (11-14) and indolinospironaphtho-1,4-oxazine (17) were synthesized by an aldol type of condensation of 1',3',3'-trimethyl-2 '-methyleneindoline and its 5-substituted derivatives with an appropriately substituted hydroxybenzaldehyde, hydroxynaphthaldehyde or nitrosonaphthol. An unequivocal proof of the stereostructures of 9 and 17 was obtained by the single-crystal X-ray diffraction method. A substituted indoline ring and the benzopyran ring in 9 and the naphtho-1,4-oxazine moiety in 17 are interconnected via the common chiral atom and positioned almost perpendicularly to each other. The five-membered 2,3-dihydropyrrolo moiety of the indoline ring adopts an envelope conformation in both structures. Of all the compounds of this series, spirobipyridopyran (1) inhibited specifically the growth of human melanoma (HBL) (IC(50): 0.9 microM) cells but not the growth of normal fibroblasts (WI38). Indolinospirobenzopyrans (8-10) showed significant cytostatic activities against all tumor cell lines. However, these compounds also exhibited a cytotoxic effect on normal human fibroblasts. The indolinospirobenzopyrans 4, 6-8, 10 and the indolinospironaphtho-1,4-oxazine 16 showed, albeit modest, selectivity as antiviral agents against varicella-zoster virus (VZV) and/or cytomegalovirus (CMV) (EC(50) within the concentration range of 1.0-12.6 microM).
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Affiliation(s)
- Silvana Raić-Malić
- Department of Organic Chemistry, Faculty of Chemical Engineering and Technology, University of Zagreb, Marulićev trg 20, PO Box 177, HR-10000 Zagreb, Croatia
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8
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Krupcik J, Oswald P, Májek P, Sandra P, Armstrong W. Determination of the interconversion energy barrier of enantiomers by separation methods. J Chromatogr A 2003; 1000:779-800. [PMID: 12877200 DOI: 10.1016/s0021-9673(03)00238-3] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Separation methods have become versatile tools for the determination of kinetic activation parameters and energy barriers to interconversion of isomers and enantiomers in the last 20 years. New computer-aided evaluation systems allow the on-line determination of these data after separating minute amount of pure compounds or mixture of isomers or enantiomers, respectively. Both dynamic interconversion during the separation process as well as static stopped-flow techniques have been applied to determine the kinetic activation parameters and interconversion energy barriers by separation methods. The use of (1) combinations of batchwise kinetic studies with enantioselective separations, (2) a continuous flow model, (3) a comparison of real chromatograms with simulated ones, (4) stopped-flow techniques, (5) stochastic methods, (6) approximation functions and (7) deconvolution methods, for the determination of interconversion energy barriers by separation methods is summarized in detail.
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Affiliation(s)
- J Krupcik
- Department of Analytical Chemistry, Slovak University of Technology, Radlinského 9, Bratislava 81237, Slovakia.
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9
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Tobler E, Lämmerhofer M, Mancini G, Lindner W. On-column deracemization of an atropisomeric biphenyl by quinine-based stationary phase and determination of rotational energy barrier by enantioselective stopped-flow HPLC and CEC. Chirality 2001; 13:641-7. [PMID: 11746796 DOI: 10.1002/chir.10015] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The reversible enantiomerization of axially chiral 2'-dodecyloxy-6-nitrobiphenyl-2-carboxylic acid was studied in the presence of a brush type chiral stationary phase based on O-(tert-butylcarbamoyl) quinine as chiral selector unit by stopped-flow high-performance liquid chromatography (sfHPLC) and capillary electrochromatography (sfCEC). After initial separation of the enantiomers in the first section of the column, the flow was stopped and the resolved species allowed to enantiomerize on-column. From this conversion, which could be determined from the enantiomeric ratios at different enantiomerization times, kinetic rate constants were calculated. By sfHPLC at a constant temperature of 15 degrees C, kinetic rate constants in the presence of the CSP were found to be 4.1 x 10(-5) s(-1) and 2.2 x 10(-5) s(-1) for the (-) and (+)-enantiomers, respectively, corresponding to half-lives of 279 and 530 min. Thus, apparent activation energies of enantiomerization were calculated to be 93.0 and 94.6 kJ mol(-1) for the (-) and (+)-enantiomers. On the macroscopic level, the apparent difference of rotational energy barriers and kinetic rate constants for both enantiomers is reflected as deracemization. For example, starting from a racemic mixture, an enantiomeric excess (ee) of 14% was seen in the stopped-flow HPLC experiment described after an enantiomerization time of 220 min at 15 degrees C, and a maximal ee of 17% can be approximated after infinite enantiomerization time. There is good agreement between HPLC and CEC results as well as their experimental errors, confirming that the new sfCEC technique may be a valuable and convenient tool to study interconversion processes.
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Affiliation(s)
- E Tobler
- Institute of Analytical Chemistry, University of Vienna, Vienna, Austria
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10
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Abstract
The four stereoisomers of chalcogran 1 ((2RS,SRS)-2-ethyl-1,6-di-oxaspiro[4.4]nonane), the principal component of the aggregation pheromone of the bark beetle pityogenes chalcographus, are prone to interconversion at the spiro center (C5). During diastereo- and enantioselective dynamic gas chromatography (DGC), epimerization of 1 gives rise to two independent interconversion peak profiles, each featuring a plateau between the peaks of the interconverting epimers. To determine the rate constants of epimerization by dynamic gas chromatography (DGC), equations to simulate the complex elution profiles were derived, using the theoretical plate model and the stochastic model of the chromatographic process. The Eyring activation parameters of the experimental interconversion profiles, between 70 and 120 C in the presence of the chiral stationary phase (CSP) Chirasil-beta-Dex, were then determined by computer-aided simulation with the aid of the new program Chrom-Win: (2R,5R)-1: deltaG(++) (298.15 K) = 108.0 +/-0.5 kJ mol(-1), deltaH(++) = 47.1+/-0.2 kJ mol(-1), deltaS(++) = -204+/-6 JK(-1) mol(-1): (2R,5S)-1: deltaG(++) (298.15 K) = 108.5+/-0.5 kJ mol(-1), deltaH(++) = 45.8+/-0.2 kJ mol(-1), deltaS(++) = -210 +/-6 J K mol(-1); (2S,5S)-1: deltaG(++) (298.15 K)= 108.1+/-0.5 kJ mol(-1), deltaH(++) = 49.3+/-0.3 kJ mol(-1), deltaS(++) = -197+/-8 J K(-1) mol(-1); (2S,5R)-1: deltaG(++) (298.15 K)=108.6+/-0.5 kJ mol(-1), deltaH(++) = 48.0+/-0.3 kJ mol(-1), deltaS(++) = -203+/-8 J K(-1) mol(-1). The thermodynamic Gibbs free energy of the E/Z equilibrium of the epimers was determined by the stopped-flow multidimensional gas chromatographic technique: deltaG(E/Z) (298.15 K)= -0.5 kJ mol(-1), deltaH(E/Z) = 1.4 kJ mol(-1) and deltaS(E/Z) = 6.3 J K(-1) mol(-1). An interconversion pathway proceeding through ring-opening and formation of a zwitterion and an enol ether/alcohol intermediate of 1 is proposed.
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Affiliation(s)
- O Trapp
- Institut für Organische Chemie, Universität Tübingen, Germany
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11
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Loncar-Tomaskovic L, Pustet N, Mrvos-Sermek D, Nagl A, Mintas M, Mannschreck A. Spirobipyridopyrans and indolinospiropyridopyrans: Synthesis, X-ray crystal structure, separation of enantiomers, and barriers to thermal cleavage of the C(sp(3))-O bond. Chirality 2001; 13:81-8. [PMID: 11170250 DOI: 10.1002/1520-636x(2001)13:2<81::aid-chir1002>3.0.co;2-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The novel chiral spirobipyridopyrans 1 and 2 were synthesized by the acid catalyzed aldol type condensation of 5-deoxypyridoxal with the appropriate ketone and subsequent reaction of the resulting pyrylium salt with base. The indolinospiropyridopyrans 3-5, which contain the modified B(6) unit, were prepared by aldol reaction of 5-deoxypyridoxal with 1,3,3-trimethyl-2-methylenindolines. Analytical separation of enantiomers was accomplished by low-pressure liquid chromatography (LPLC) on triacetylcellulose. The barriers to thermal racemization were determined by on-line measurements of the enriched enantiomers after LPLC. Gibbs energies of activation DeltaG superset, not equals for reversible cleavage of the C(spiro)-O bond in 1, 3, and 4 were in the range 103-108 kJ/mol. The lower limits of the barriers in 2 and 5 were estimated to be greater than 102 and 109 kJ/mol by attempted thermal racemizations. The increase of the barriers from 3 to 4 and 5 was explained by the influence of electron withdrawing groups, which reduce the stability of the ring-opened transition states to C(sp3)-O bond cleavage. Geometrical data from X-ray structure analysis showed that the angle [C3-C2-C3'] around the spiro carbon atom increases with elongation of the chain in the C3-C3' bridge. This angle widening is explained by a ring-strain effect, which is greater in the five-membered ring in the skeleton of 7 than in the six- and seven-membered rings of 1 and 2.
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Affiliation(s)
- L Loncar-Tomaskovic
- Department of Organic Chemistry, Faculty of Chemical Engineering and Technology, University of Zagreb, Zagreb, Croatia
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12
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Kießwetter R, Pustet N, Brandl F, Mannschreck A. 1′,3′,3′-Trimethyl-6-nitrospiro[2 H -1-benzopyran-2,2′-indoline]: its thermal enantiomerization and the equilibration with its merocyanine †Chiral 2H-pyrans, Part 10. Part 9: Ref. 1. †. ACTA ACUST UNITED AC 1999. [DOI: 10.1016/s0957-4166(99)00538-8] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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